Improvement in heating-furnaces



2 Sheet s-Sheet 1,

W. D. BARTLETT.

Hot-Air Furnace.

1 4g. zPatented March 22. 1870' El E1 N- PETERS, PHOTO LITNQGRAFHER,WASHINGTON. D C.

2 Sheets-Sheet 2 W. D. BARTLETT.

Hot-Air Furnace. N0.101,082. Patented March 22, 1870.

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WILLIAM D. BARTLE'ITI, OF AMESBURY; MASSAOHUSETITS.

Letters Patent No. 101,082, dated JIarch 22, 1870.

IMPROVEMENT IN HEATING-FURNACES.

The Schedule referred to in these Letters Patent and making part of thesame To all whon'rit may concern Be it known that ,1, WILLIAM 1).Banqrnn'rr, of

vention sufiicient to enable those skilled in the art to practice a it.

A furnace embodying my invention is seen in plan in'Figure 1 of thedrawings; in vertical central section in Figure 2, the section beingtaken in the plane of the line z z, fig. 1; and in verticalcross-section in Figure 3, the section being taken in the plane of theline yy,ifigs. 1 and 2. v y The furnace is erected on a suitable base,a, over which, at a height sufficient to give an ash-pit beneath, is seta fire-pot, I), provided with a grate, j, suitable for burning coal.

All around the sides and rear of the fire-pot is left a flue-space, c,communicating with a long high baseflue, (Z, of a width equal to thedistance apart of the inner side walls 6 e of the furnace.

The ash-pit f is olosed'ofi from the flue ll by a removable partition,9, so that when it is desirable to burn wood instead of coal, thepartition y isremovcd,

the coal-door at h is shut, and long cord-wood isintroduced at theash-door i beneath grate j, and, being ignited,-is consumed on thebottom of the flue (Z.

The side walls e c, are connected by cross-plates, which make withinsaid walls a tortuous flue through which the volatile products ofcombustion pass from the rear end ofthe flue d to the chimney-funnel 7;,in the direction indicated by the arrows on the drawing.

These plates may be double, as shown, so to give space between them intowhich cool air may enter through apertures in one side-wall c, and bedischarged, when heated, through apertures in the other side-wall 0'.

Over and around the fire-pot a wall, 7, is built, preferably of fire'brick, to make a combustion-chainher, from which the volatile productsof combustion proceed with a downward draught into the flue d.

Outside of the side walls e c, the walls in in are erected, so as toleave air-spaces between the walls 0 1: and m m, and cool air isadmitted under proper control into the side box a through apertures inthe lower part of wall or, into the space between walls m and c.

The space included between the lower cross-plates o 0 is closed at therear, and also at the front, where said plates abut against the wall ofthe combustionchamber, and the lower plate 0 is preferably protected bya facing of fire-brick, p, or other suitable. material, from becomingoverheated.

The front wall of the furnace is marked 1 and the rear wall 0', and inpractical use they should be made thick, if not double, to preventradiation therefrom.

The next higher set of cross-plates, .o o, abuts against the rear wall,but does not reach the front wall, and the third and fourth sets ofplates 0 o are arranged similarly to the first and second setsrespectively, openings being made for circulation of pure air throughsaid spaces as before described, so that plates 0 0 are radiatingsurfaces for-heating the air which passes between them, in moving fromthe cold-air space s between walls in. and c to the warm-air space t,between the walls or and 0'.

The plate it forms the top of the space which is occupied by thevolatile products of combustion, and it extends also over the top of thecold-air space 3.

The wall (1 is continued upward to the same height with the wall in andthe walls (1 and r, the space included thereby and by the plate u andthe top n of the furnace forming the upper hot-air space or chamber '20,from which the heated air is conveyed to its destination throughdistributing-pipes 1 1r.

Under the second set of plates 0 o, and under the other sets above, areinserted, in the walls e c, openended pipes a, which may act as supportsfor the low er plate 0 of each set.

These pipes a receive cool air from the space 8, and pass it when andheated into the hot-air chamber i, from which it passes into the chamber20, and out of the pipes .r .r.

To increase the ciiiciency of the pipes at as heaters of the air passingthrough them, I place in the ends thereofopcnin g into the space 8 pcrtbrated diaphragms -b, which contract the openings into the pipes, and

allow the cool air to expand therein and check the rapidity of the. flowof tho air-currents through said pipes.

In the cool-air spaces I place dampers or valves, 0, by the position ofwhich 1 can control the amount or cool air flowing into the upper orlower cross air-fines.

In the rear wall opposite each upper plate 0, 1 make clcauing-out holes,through which the solid depositon said plates canbe brought into thelower flue by moving it in directions opposed to those indicated by thearrows in fig. 2, and the lower flue d can be cleared of all depositedmatter through the ash-door at 5, after having removed the movablepartition 9.

For the plates 0 o inclosing air-spaces may be substituted solid platesresting on the air-fines a, the pipes a in said case being then the onlyconduits connecting the air-spaces s and f.

The furnace may be made up mostly of iron, either wrought or cast, oritmay be made, with exception of the lire-pot, grate, doors, dampers, &cof brick, soap-stone, &c., and the pipes a may be of some kind of clay.\Vhcn made with the least possible amount a of metal, tl-icheatli'om thefurnace will be soft and mild, and the air proceeding from it will beuncontaminated with the coal-gases which are now supposed to passthrough heated cast-iron.

The draught of the furnace is to be regulated by dampers or valves inthe fire and ash-pit doors, and by a valve in the smokefunnel, by whichmore or less air can be admitted into or excluded from it.

Furnaces made as shown and described have so large an area ofradiating-surface that all the heat generated from combustion of fueltherein is communame Also, the elevated fire-pot b, the down-draft fluec, base-flue d, movable partition g, and ash-pit f, combined andarranged as and for the purpose specified.

Also, the arrangement of the air-flues a, as described, when made withcontracted entrances for the cold air, and full openings for the escapeof the hot air, as described.

Also, the arrangement of a damper or dampers c in the vertical cold-airspace 3, so as to cause the cold air to pass more or less through theupper or lower air-fines on its way to the hot-air space t, as may bedesired.

WM. D. BARTLETT.

Witnesses:

J. B. GnosnY, S. B. KIDDER.

